-PRO 140 has potential to be the key to successful treatment substitution therapy-

VANCOUVER, WA, USA I February 18, 2014 I CytoDyn Inc. (CYDY), a biotechnology company focused on the development of new therapies for combating infection with immune deficiency viruses, announced today that the Company has submitted a Phase 2b clinical trial protocol, for its lead product candidate, PRO 140, to the U.S. Food and Drug Administration for treatment substitution in patients with Human Immunodeficiency Virus (HIV). PRO 140 is a humanized monoclonal antibody directed against CCR5, a molecular portal that HIV uses to enter cells, and belongs to a class of HIV therapies known as entry inhibitors that block HIV from entering into and infecting certain cells. In this Phase 2b study, the Company’s primary objective is to assess the efficacy of PRO 140 monotherapy for the maintenance of viral suppression in HIV patients who are stable on combination antiretroviral therapy, known as HAART (highly active antiretroviral therapy), but need or wish to discontinue HAART therapy temporarily.

Nader Pourhassan, Ph.D., CytoDyn’s President and Chief Executive Officer, stated, “We believe our treatment substitution study has the potential to provide a drug holiday to patients from their daily pill regimen. PRO 140 could be the key to maintaining viral load suppression during a drug holiday. If the study has a positive outcome, we believe this may address a significant unmet medical need and have high patient acceptance.”

David Feigal, M.D., CytoDyn’s Chief Medical Officer, commented, “We are entering an important phase with our plans for advancing the development of PRO 140. I am excited to be leading the clinical development of PRO 140 and look forward to exploring its utility in treatment substitution. Importantly, I believe we are another step closer to bringing the first antibody for the treatment of HIV to the market.”

Dr. Feigal added, “The FDA recently approved the study drug manufacturing and quality (CMC) of PRO 140 in connection with use in other clinical trials. While we await receipt of FDA comments on our treatment substitution protocol, we are working on selecting study sites and preparing to launch patient screening and enrollment for the study.”

Dr. Pourhassan concluded, “I am energized by our prospects of further unlocking the potential of PRO 140 and believe the treatment substitution indication has the potential not only to address patient needs but also to advance CytoDyn to our next phase of development. Our priorities are clear, and our team is committed to aggressively advancing PRO 140 with the goal of providing ground-breaking advancements in the treatment of HIV.”

About PRO 140

PRO 140 belongs to a new class of HIV/AIDS therapeutics — viral-entry inhibitors — that are intended to protect healthy cells from viral infection. PRO 140 is a humanized monoclonal antibody directed against CCR5, a molecular portal that HIV uses to enter cells.

PRO 140 has been the subject of four Phase 1/1b and two Phase 2a clinical trials, each of which demonstrated PRO 140’s ability to significantly reduce HIV viral load in human test subjects, and has also been designated a “fast track” product candidate by the FDA. The PRO 140 antibody appears to be a powerful antiviral agent while not being a drug, leading to potentially fewer side effects and less frequent dosing requirements as compared to daily drug therapies currently in use.

About CytoDyn

CytoDyn is a biotechnology company focused on developing subcutaneously delivered humanized cell-specific monoclonal antibodies (mAbs) as entry inhibitors for the treatment and prevention of Human Immunodeficiency Virus (HIV). The Company has one of the leading mAbs under development for HIV infection, PRO 140, which is a Late Stage 2 humanized mAb with demonstrated antiviral activity in man. PRO 140 blocks the HIV co-receptor CCR5 and clinical trial results thus far indicate that it does not affect the normal function of the cell. Results from Phase 1/1b and Phase 2a human clinical trials have shown that PRO 140 can significantly reduce viral burden in people infected with HIV. CytoDyn intends to continue to develop PRO 140 as a therapeutic anti-viral agent in persons infected with HIV. For more information on the Company please visit www.cytodyn.com.

SOURCE: CytoDyn